People enjoy eating quality food that is prepared by good restaurants. Nevertheless, sometimes people may not want to go to a restaurant, but instead may prefer to have food delivered to them. To meet this demand, a courier may deliver food prepared by a restaurant to a customer at a delivery location. For example, a service may enable customers to order food items from any of a variety of restaurants, and may arrange for couriers to deliver the food items from the restaurants to the customers. After an order has been placed, the customer may sometimes want to add one or more additional items to the order. However, this may disrupt the preparation of the earlier order, may result in a separate new order, or may cause other complications that diminish the customer experience.